As I stated before n2 in shocks, airplane struts. Racing tires for build up of heat and stability as we raced motorcycles up to 160 mph, n2 did not give us any failures. N2 is not needed for highway tires, and n2 put in then air put in n2 was contaminated then useless.

There is a logic to this, but it isn't because of the nitrogen, as has been noted above. It is because the bottled nitrogen is dry. Moisture is the problem for pressure stability with varying temperature, as water vapour expands much more than air/nitrogen. You can put a dryer on your compressor to remove the moisture, or you can use nitrogen which is already dry.

I'm not completely buying the water in racing tires theory. I concede that liquid water would affect pressure buildup and you would get more with liquid water in the air chamber.

But I strongly suspect the reason nitrogen is used in racing tires has more to do with the fact that a nitrogen bottle is easier to transport than an air compressor.

In the 1970's I used to crew for an IMSA race team. They used nitrogen bottles to power the impact guns for tire changes. Those did not take up a lot of space, it was easy to transport into the hot pits and one bottle could last the whole weekend. We used that bottle to fill the tires. Easy-Peasy!

I'm not completely buying the water in racing tires theory. I concede that liquid water would affect pressure buildup and you would get more with liquid water in the air chamber.

But I strongly suspect the reason nitrogen is used in racing tires has more to do with the fact that a nitrogen bottle is easier to transport than an air compressor.

In the 1970's I used to crew for an IMSA race team. They used nitrogen bottles to power the impact guns for tire changes. Those did not take up a lot of space, it was easy to transport into the hot pits and one bottle could last the whole weekend. We used that bottle to fill the tires. Easy-Peasy!

We did not start using n2 until the 80s & we found the tire pressure did not go up and very few failures of which we had none versus air filled. When you are racing on 2 wheels at 160mph w/out roll cage seat harness ore other safety devices that cars have, we don't take chances with tires etc. You will get or killed or hurt if falling at these speeds this is not IMSA with a open or closed cage around you & technology has changed since 70s enuf said on this matter as I stated before n2 is not needed for highway use &waste of money unless free. PS I owned the bikes we raced & did all work both on & off track. We raced grand national races all over US & had top pros ride for me & my 2 sons so I did not take chances with there lives